Appraisal of groundwater potentiality of multilayer alluvial aquifers of the Varuna river basin, India, using two concurrent methods of MCDM

Abstract

An approach has been made in this study to delineate the groundwater potential zones of the Varuna river basin, Uttar Pradesh, India, using the analytical hierarchy process (AHP) and multi-influence factor (MIF) techniques. The present groundwater estimation exhibits an increase in the draft (10%) due to expansion in population, agricultural extent, and industrialization, which ultimately causes water table depletion. This backdrop justifies the need for this particular analysis in the multilayer aquifers of the central alluvial zone. The shallow aquifers are silty and unconfined, whereas the deeper aquifers are coarse, sandy-gravelly, and semi-confined. Basement faults and highs often control the thickness of aquifers in the subsurface. The study considered an integrated approach of AHP and MIF methods with remote sensing and GIS approaches. Various themes (land use/land cover (LULC), soil type, geology, elevation, slope, rainfall, normalized difference vegetation index (NDVI), drainage density, recharge rate, groundwater depth) determined by considering different conditioning factors and eventually employed for computation of groundwater potential index (GWPI) and classified for identifying the groundwater potential zones (GWPZ). Two methods applied to capture the results in a more tangible form as the AHP model works on building a pair-wise comparison matrix to relate conditioning factors to each other. Still, the MIF model considered interrelations among the conditioning factors. The GWPZ of the study area generates with overlay weighted sum method by integrating all thematic layers. The resulting groundwater potential index map is categorized into three groundwater potential zones, namely good, moderate, and poor. Ultimately, by constructing the receiver operating characteristic (ROC) curves for both the groundwater potential models, determine the efficiency of performances and the GWPZ map validated using yield data collected from wells scattered over the study area. The findings of the present paper have important implications for ensuring exploration and sustainability groundwater plans in that particular area.